Lactate and Echocardiography Before Veno-Venous Extracorporeal Membrane Oxygenation Support

BACKGROUND

Lactate has been recognised as a prognostic factor in several critical conditions. Veno-Venous Extracorporeal Membrane Oxygenation (VV-ECMO) is a well-established therapy in patients with Acute Respiratory Disease Syndrome (ARDS) unresponsive to conventional therapy and echocardiography pre ECMO initiation has been recently reported to help in risk stratifying these patients.

METHODS

We assessed whether the detection of hyperlactataemia could be associated with the presence of left ventricle (LV) or right ventricle (RV) dysfunction in 121 consecutive patients with refractory ARDS.

RESULTS

The mortality rate was 42.9% (52/121). Higher dosages of norepinephrine and dobutamine were administered to non survivors (p=0.023 and p=0.047, respectively) who showed significantly higher levels of lactate (p=0.002). At echocardiography, non survivors showed higher values of systolic pulmonary artery pressure (sPAP) (p=0.05) and a higher incidence of RV dysfunction (as indicated by lower Tricuspid Annular Plane Excursion (TAPSE)) and RV dilatation (p=0.001). At multivariate logistic regression analysis, the following variables were independent predictors of death: body mass index (BMI) (OR: 0.914, 95%CI 0.857-0.975, p=0.006), RV dilatation (OR: 0.239, 95%CI 0.101-0.561, p=0.001) and lactate (OR: 1.292, 95%CI 1.015-1.645, p=0.038). Lactate values were directly correlated with the simplified acute physiology score (SAPS) II (r=0.38, p<0.001), while they showed an indirect correlation with left ventricular ejection fraction (LVEF) (r=-0.24, p=0.009) and TAPSE (r=-0.21, p=0.024).

CONCLUSIONS

In refractory ARDS, hyperlactataemia before VVV-ECMO identified a subset of patients at higher risk of death, being an independent predictor of in-Intensive Care Unit (ICU) mortality. Lactate values are mainly related to disease severity (as indicated by SAPS II) and haemodynamic impairment (as inferred by LVEF) and RV failure, as (indicated by TAPSE).

Right ventricle dilation as a prognostic factor in refractory acute respiratory distress syndrome requiring veno-venous extracorporeal membrane oxygenation

BACKGROUND

The aim of this study was to assess the incidence and prognostic role of echocardiographic abnormalities in consecutive patients with refractory acute respiratory distress syndrome (ARDS) before veno-venous extracorporeal membrane oxygenation (VV-ECMO).

METHODS

In this study 74 consecutive patients with refractory ARDS underwent echocardiography (transthoracic, transesophageal or both, according to the best acoustic window). Baseline characteristics were collected for all patients and the simplified acute physiology score was calculated. At echocardiography the following parameters were considered: left ventricle (LV) ejection fraction, right ventricle (RV) size and function (by means of tricuspid annular plane excursion [TAPSE]) and systolic pulmonary arterial pressure.

RESULTS

At echocardiography, 25 patients showed normal findings (33.8%), 32 patients exhibited isolated pulmonary hypertension (43.2%) and the remaining 17 patients showed RV dilation and pulmonary hypertension (23%). A reduced LVEF (<50%) was observed in 14 patients (18.9%), while RV dysfunction (as indicated by TAPSE<16 mm) was documented in 21 patients (28.4%). The in-Intensive Care Unit [ICU] mortality rate was 41.8%. At stepwise regression analysis the following variables were independent predictor for in-ICU mortality (when adjusted for TAPSE<16 mm): RV end diastolic area/LV end diastolic area (OR 0.21, 95%CI 0.062-0.709, P=0.012), Body Mass Index (BMI) (OR 0.87, 95%CI 0.802-0.958, P=0.004) CONCLUSIONS: In consecutive patients with refractory ARDS, echocardiographic alterations were common, mainly represented by systolic pulmonary hypertension associated or not with RV dilatation. Moreover, RV dilatation and BMI were independent predictors of in-ICU mortality. On clinical grounds, our findings strongly suggest that echocardiography helps to risk stratifying patients with refractory ARDS requiring VV-ECMO.

Pulmonary vascular dysfunction in refractory acute respiratory distress syndrome before veno-venous extracorporeal membrane oxygenation

BACKGROUND

Pulmonary vascular dysfunction has been described in patients with acute respiratory distress syndrome (ARDS). Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a well-established treatment for these patients. We hypothesized that severe pulmonary vascular dysfunction and cor pulmonale identified by echocardiography before cannulation in these patients were associated with worse survival.

METHODS

Echocardiography was used to identify pulmonary hypertension in 21 patients with refractory ARDS just before ECMO implantation. Survival was compared for those with and without cor pulmonale.

RESULTS

In our series, the overall mortality rate was 57.1% (12/21). Echocardiographic exams were transthoracic in 5 patients (23.8%), transesophageal in 4 patients (19%), and both (transthoracic and transesophageal) in the remaining 12 patients (57.1%). In our series, six patients (28.5%) showed LV dysfunction. Acute cor pulmonale was detectable in 2 patients (9.5%), while the remaining 19 patients showed moderate pulmonary dysfunction. Survivors had a higher pre-cannulation LV ejection fraction (EF) (P = 0.02) and tricuspid annular plane excursion (P = 0.04), and lower peak systolic pulmonary artery pressures (P = 0.02).

CONCLUSIONS

In patients with refractory ARDS immediately before ECMO implantation, the prevalence of acute cor pulmonale is low (9.5%). Survival is associated with higher LVEF and lower systolic pulmonary arterial pressure. These findings support the idea that echocardiographic assessment of pulmonary artery pressure in patients with refractory ARDS before VV-ECMO implantation may have value for risk-stratification.

[Adolescents and breast feeding]

The attitudes and future decisions of teenage girls towards infant feeding methods, breast-feeding or bottle feeding have been investigated. A self-conducted questionnaire was completed by 146 secondary school girls ranging in age from 16 to 18 years. Economic convenience, better nutritional value, deeper emotional link with the infant, own and friends past experience nearly always in favour of breast-feeding, represent for the girls the main advantages of breast-feeding. On the other hand, many girls apprehend breast-feeding for various possible physical, psychological and social implications. Some aspects of the problem studied in this paper show a significant correlation with the future choice of infant feeding. The girls would be interested in receiving information at school. Suitable information during school health lessons may positively influence teenage girls to adopt breast-feeding as the infant feeding method of choice.